The invention concerns a test device for testing semiconductor substrates, known as a prober. Testing often occurs under special environmental conditions with respect to temperature and atmosphere, for example, under elevated temperature in a nitrogen atmosphere. The nitrogen atmosphere then serves to avoid corrosion of the elements of the test substrate. The test arrangement for such special test conditions is surrounded by a housing, which accomplishes the required temperature shielding or the required pressure-tight closure or both relative to the surrounding atmosphere.
Such test devices regularly have a chuck within the housing, i.e., a holding device for the test substrate, which is adjusted with respect to the surface and mechanical and electrical, and optionally also chemical properties, to the semiconductor substrate being tested and the test conditions. Both wafers with individual components formed on them and individual components in different manufacturing stages are considered as semiconductor substrate.
The semiconductor substrate arranged on the chuck has contact surfaces, which are contacted with correspondingly adjusted test tips mechanically and electrically for the test, in order to act upon the semiconductor substrate with a signal or tap an output signal. Depending on the type of test, contacting can also last a few minutes to hours, in order to test, for example, the reliability of the substrate under continuous operation under comparable or intensified conditions. For such longer-lasting tests, the geometric accuracy of contacting is especially significant.
Positioning of the test tips relative to the contact surfaces of the semiconductor substrate occurs by means of appropriate positioning devices, with which the relative position of both contact partners can be produced by either moving the chuck alone or the chuck and the test tips in the three spatial directions X, Y and Z.